Potable fresh water tank

etu · August 24, 2015

We've owned and camped several years in our 2004 Keystone Challenger 5w but we've never used the fresh water tank. Guy we bought it from 5 years ago had also never used it either. We are going on a trip next month and may need to boondock one or 2 nights so I thought I'd read up on it. The manual is not very detailed ("it's automatic, fill with water and turn on the switch on the water tank monitor").

Anyway I filled it and opened the faucets and turned on the switch and everything works fine. But I still don't understand fully how it works. For example, when using city water, what keeps the city water from running through the pump and into the fresh water tank. And now that I have it full how do I drain it? I want to drain it and refill with disinfecting solution. Thanks

usaperuvian · August 24, 2015

I may not know how to drain your tank but here is an article on cleaning your water tank.

HOW TO SANITIZE YOUR RV FRESH WATER TANKS

APRIL 9, 2014 PEOPLE & PLACES 8 COMMENTS

Yuck. Nothing tastes worse that the first sip of water through a just de-winterized RV’s plumbing system on the first trip of the year. That’s why it is important to sanitize that fresh water tank. And for that, there are lots of different approaches.

Everybody seems to have their favorite way of sanitizing the fresh water system.

Roadtrek Motorhomes has a suggested way, though. Here it is, how to sanitize your fresh water tanks, lifted from the instruction manual for the eTrek we use. There are similar instructions for all Roadtrek models. Find yours by clicking toroadtrek.com/manuals.aspx and then reading the section on de-winterizing.

Some people will disagree with this and think it overkill. Others will say it’s not enough. But for me, this is what I plan to do.

Note: If you follow this completely, it takes a lot of time, ideally a couple of days at least. And this is for the fresh water system. Your hot water system also needs to be de-winterized. But since there are so many differences in the way the different models heat water, you can look up your recommendations in the manual specific to your vehicle.

Roadtrek suggests a two step fresh water sensitization process:

First step

You will need 2 gallons of water and 1 cup of fresh bleach. (Bleach loses its potency over time; always start with bleach that is less than 6 months old.)

Mix up two gallons of water and one cup of chlorine bleach. Add to the fresh water fill. Allow a few minutes to drain into exterior tank.
This is a good time to get some stuff for spring cleaning of your Roadtrek, so drive around for an hour. Let it sit for a couple more hours. The driving sloshes it around in the tank. That is good.
When you get home again, open the drain valve and drain both tanks.

This kills any bacteria in the tanks before you distribute them through the entire water system.

Second step

Mix 1/2 cup of chlorine with 2 gallons of water and pour into fresh water fill.
Fill fresh water tank about 1/2 full.
Add 1/2 cup of chlorine and fill fresh water tank about 3/4 full.
Turn on water pump, circulate through entire system.
Run water out of every faucet and shower head until you smell chlorine.
With the water pump on, open the city water valve, and let the pump push water through the fill line for a minute or so.
Run the galley faucet for several minutes. If you smell chlorine, your system is safe to use. If you do not smell chlorine or your water is foamy, or has a pungent odor, repeat this step.
Drain completely, fill fresh water tank with clean water, run all faucets for 2-3 minutes each.
To help get rid of the residual chlorine smell, pour a cup of vinegar into the fresh water tank, fill, let sit for a few hours, run the faucets for a minute or so apiece, drain the tank to ground, and refill with fresh water.

There you go. Let us know how it works for you or what your process of sanitizing happens to be.

http://roadtreking.com/sanitize-fresh-water-tanks/

Rif · August 24, 2015

As for why the water does not flow into the tank when connected to city water, there is a check valve in the pump that permits water to flow only one way.

etu · August 24, 2015

Thanks for the replies. Ill use those tips to sanitize. There are only 2 drain ports at the underside; one is cold line the other hot. These two are teed into the hot and cold lines just above the the storage area floor. (this floor covers the grey,black and fresh tanks)These drains would be low points in the water lines when using city water but the fresh water tank is located below where these drains tee into the water lines. There is no way to see the tanks unless you remove the under belly panel.

I suppose I could open those drains and turn on the pump and it would eventually pump out the tank. Any other suggestions appreciated.

Rif · August 24, 2015

I'd look again. Usually there is a drain from the low point in the tank. Sometimes it is a separate line and valve, and sometimes it is in the line from the tank to the water pump. I've never seen a rig that did not have one.

Kirk W · August 25, 2015

I agree with Rif. Look in the area of the fresh water tank as there is almost always a drain valve in the line between the tank and the suction of the pump. The pump operates based upon pressure in the water lines, when you turn it on it will run briefly and then stop, starting again when you open a faucet or flush the toilet. When you connect to city water just leave the water pump turned off. RV water pumps are designed to work as a check valve when turned off and do not allow water to back flow to the tank.

WeBeFulltimers · August 25, 2015

If I were you I would properly sanitize the tank as instructed but would use bottled water for coffee, cooking, etc.

Kirk W · August 25, 2015

If I were you I would properly sanitize the tank as instructed but would use bottled water for coffee, cooking, etc.

If you sanitize properly, why waste your money buying water that is just some city system that's been filtered? Get your own filter system to put between your RV and the supply and filter what goes into the tank or the system yourself? We have used our water system for all of our RV history and our own water filter for about the past 20 or so years.

oscarvan · August 25, 2015

What Rif and Kirk said. There's a drain somewhere.

etu · August 26, 2015

Ok you all were right. There is a drain located between the 2 axles. Well hidden and considerably far back from the inlet and the hot/cold water line drains. Had to get down and crawl under to see it. Thanks for all the help.